[除錯] DataGridView SelectionChanged 點到表頭會出錯

'點到表頭會出錯
 If DataGridView1.CurrentRow.Index <> -1 Then

 End If

'改成
 If DataGridView1.CurrentRow IsNot Nothing Then

 Endif


'確定是否點選到DataGridView的某行資料列 [C#]
if (this.DataGridView.SelectedRows.Count != 0) {}


參考：
C# datagridview selectionchanged event error
You're likely getting this error because its trigger the event when it's not a valid selection (ie. -1) thus throwing this exception.
DataGridView - EditOnEnter

環境：
VS 2008
.Net 3.5